%\scrollmode
\tracingstats=1000
\noautoxspacing
\newlinechar=`\^^J
\font\x=ec-lmtt10 \x
\immediate\openout1=\jobname.out
\def\MSG#1{%
  \message{\string{MSG #1\string}}%
  \immediate\write17{\string{TOT #1\string}}%
  \immediate\write1{#1}%
}
\def\head#1{\message{■#1.}\par\noindent\hbox{■\null}#1.\par}
\message{^^J}

%================
\def\A{^^c5^^bf ſ 顛 }
A: \A

\MSG{\A}
\show\A

%================
\par
\head{\string\meaning}

\edef\B{\meaning\A}
\meaning\B

\B
\MSG{\meaning\B}
\show\B

%================
\head{\string\jobname}
\edef\C{:\jobname:}
\MSG{*あ*\jobname *\C*\meaning\C*}
\message{^^J}

%================
\catcode`\^^c5=11
\catcode`\^^bf=11
\catcode`\^^e1=11
\catcode`\^^e3=11
\catcode`\^^81=11
\catcode`\^^82=11

\head{oneletter}

\string\^^c4.\string\^^c5.\string\^^ff.
\count0=`\^^c5%
\MSG{\string\catcode`\string\^^c5 = \the\count0}%
\count0=`^^c5%
\MSG{\string\catcode`^^c5 = \the\count0}%
\count0=`^^c5^^bf%
\MSG{\string\catcode`^^c5^^bf = \the\count0}%
\count0=`顛%
\MSG{\string\catcode`顛 = \the\count0}%

%================
\head{csname1}

{\def\顛{hoge}\def\^^c5^^bf{piyo}
\show\顛
\show\^^c5^^bf
\expandafter\show\csname ^^c5^^bf\endcsname
\MSG{\string\顛=>\meaning\顛}
\MSG{\string\^^c5^^bf=>\meaning\^^c5^^bf}
\MSG{\expandafter\string\csname ^^c5^^bf\endcsname
  =>\expandafter\meaning\csname ^^c5^^bf\endcsname}}

\string\^^c5^^bf
\expandafter\string\csname ^^c5^^bf\endcsname,
\expandafter\string\csname ſ\endcsname,
\expandafter\string\csname 顛\endcsname
\MSG{\string\^^c5^^bf,
  \expandafter\string\csname ^^c5^^bf\endcsname,
  \expandafter\string\csname ſ\endcsname,
  \expandafter\string\csname 顛\endcsname.}

%================

\def\あ{hoge}
\message{^^J}
\def\TEST#1#2{%
  \expandafter\def\csname#2\endcsname{piyo}
  \par\toks0={#2}
  \expandafter\string\csname #1\endcsname => \csname #1\endcsname,\par
  \expandafter\string\csname #2\endcsname => \csname #2\endcsname,\par
  \expandafter\string\csname \the\toks0\endcsname => \csname \the\toks0\endcsname.
  \MSG{%
    \expandafter\string\csname #1\endcsname => \csname #1\endcsname,
    \expandafter\string\csname #2\endcsname => \csname #2\endcsname.
    \expandafter\string\csname \the\toks0\endcsname => \csname \the\toks0\endcsname.
  }%
}
\ifnum\euc"A4A2="A4A2\relax
  \TEST{あ}{^^a4^^a2}
\else
  \TEST{あ}{^^e3^^81^^82}
\fi

%================
\head{0xFF}
\catcode"FF=11
\message{^^J}

\def\^^ff^^c5^^ff^^bf{あ}
\edef\E{(\string\^^ff^^c5^^ff^^bf:\meaning\^^ff^^c5^^ff^^bf)}
\^^ff^^c5^^ff^^bf, \E, \string\^^ff^^c5^^ff^^bf, \meaning\E.
\MSG{\^^ff^^c5^^ff^^bf, \A, \string\^^ff^^c5^^ff^^bf, \meaning\E.}

\def\^^ff{い}
\edef\E{(\string\^^ff :\meaning\^^ff)}
\^^ff, \E, \string\^^ff, \meaning\E.
\MSG{\^^ff, \E, \string\^^ff, \meaning\E.}

\immediate\closeout1

%========
\head{contexts}

\errorcontextlines=10000
\def\@{\A\undefined}
\edef\a{^^c5^^bf a\A\noexpand\@ ſ 顛 }
\edef\+#1{\noexpand\^^c5^^bf\noexpand\顛\noexpand\^^ff^^c5^^ff^^bf#1
  \noexpand\^^ff\meaning\A\noexpand\^^c5^^bf\noexpand\顛}
\+\a

\^^ff^^c5^^ff^^bf ^^c5^^bf \^^c5^^bf ſ顛\a \^^ff ^^ff\^^c5^^bf

\^^c5\^^ff\^^c4\^^fe

\catcode`\^^c5=11
\catcode`\^^be=11
\catcode`\^^bf=11
\catcode`\^^bd=11
\catcode`\^^ff=11
\font\x=ec-lmtt10 \x\scrollmode

\def\^^c5^^bf{a}
\def\顛{b}
\def\転{c}
\message{\string\^^c5^^bf \string\^^ff^^c5}

\def\b{\ž.\ſ.\Ž..\転.\顛.\貼.}
\b

\ž.\ſ.\Ž..\転.\顛.\貼.


%========
\head{csname2}

SHOW \show\ſ.\show\顛.%
\expandafter\show\csname ſ\endcsname.%
\expandafter\show\csname 顛\endcsname

STRING \string\ſ.\string\顛.%
\expandafter\string\csname ſ\endcsname.%
\expandafter\string\csname 顛\endcsname

MEANING \meaning\ſ.\meaning\顛.%
\expandafter\meaning\csname ſ\endcsname.%
\expandafter\meaning\csname 顛\endcsname.%

\message{\string\^^e3^^81^^82 \string\あ}

\end
